1. Technical Field
The present disclosure relates to electrosurgical instruments used for open and endoscopic surgical procedures for sealing or fusing tissue. More particularly, the present disclosure relates to a bipolar forceps for sealing vessels, vascular tissues and soft tissues by perforating vessels and/or tissue and applying energy in the vicinity of the perforated area to reduce energy consumption and facilitate extraction of collagen and elastin during an electrosurgical procedure.
2. Background of the Related Art
Open or endoscopic electrosurgical forceps utilize both mechanical clamping action and electrical energy to effect hemostasis. The electrode of each opposing jaw member is charged to a different electric potential such that when the jaw members grasp tissue, electrical energy can be selectively transferred through the tissue. A surgeon can cauterize, coagulate/desiccate and/or simply reduce or slow bleeding, by controlling the intensity, frequency and duration of the electrosurgical energy applied between the electrodes and through the tissue.
Certain surgical procedures require more than simply cauterizing tissue and rely on the combination of clamping pressure, electrosurgical energy and gap distance to “seal” tissue, vessels and certain vascular bundles. More particularly, vessel sealing or tissue sealing utilizes a unique combination of radiofrequency (RF) energy, clamping pressure and precise control of gap distance (i.e., distance between opposing jaw members when closed about tissue) to effectively seal or fuse tissue between two opposing jaw members or sealing plates. Vessel or tissue sealing is more than “cauterization”, which involves the use of heat to destroy tissue (also called “diathermy” or “electrodiathermy”). Vessel sealing is also more than “coagulation”, which is the process of desiccating tissue wherein the tissue cells are ruptured and dried. “Vessel sealing” is defined as the process of liquefying the collagen, elastin and ground substances in the tissue so that the tissue reforms into a fused mass with significantly-reduced demarcation between the opposing tissue structures.
Existing electrosurgical forceps utilize a pair of jaw members having metal electrodes to grasp and hold tissue during a sealing procedure. The metal electrodes deliver RF energy to tissue and the electric current conducted by the tissue releases heat that eventually seals the tissue. This approach may be inefficient and result in unnecessary energy consumption. For instance, even if tissue between jaw members contains a single vessel, traditional RF energy-based tissue sealing instruments would seal the entire volume of tissue between the jaws that would lead to energy loss as well as increasing the possibility of collateral damage. Further, because electrodes are made from metal, which has high heat conductivity, such electrodes may be responsible for significant heat loss. Additionally, although grasping and holding tissue facilitates tissue damage and extracting and mixing of elastin and collagen, a sufficient amount of elastin and collagen is not released.